The PLN-1LA10 Loop Amplifier is a cost-effective amplifier designed to drive a wire loop installed in the floor or ceiling, covering an area of up to 600 m2 per amplifier. This solution enables hearing-aid users in the area enclosed by the wire loop to hear all announcements, or music. Hearing-aid users can set their devices to the T-mode setting to receive the signal coming from the loop. They receive announcements in excellent audio-quality, without the background noise or reverberations that normally impair intelligibility for people with hearing disabilities.
The loop amplifier can be connected to a mixing amplifier’s line level output, or it can accept up to two microphone/line signals directly. A 100 V priority input is available for uplink to a Plena Voice Alarm System. This input can be monitored for the presence of a pilot-tone. The built-in supervision monitors all key functions of the loop amplifier, and the fault state is available on a fail-safe relay. This makes it possible to use the loop amplifier in an emergency sound system, and to include the induction loop in the supervised transmission paths.
For added ease, the loop amplifier is equipped with a limiter that keeps the output field strength below the prescribed 100 mA/m. This circuitry can also be set to an automatic gain control (AGC) that amplifies weak signals for enhanced intelligibility, while attenuating loud signals. This ensures that all information is presented at a comfortable listening level. The unit has tone controls and a metal loss compensation circuit to adjust the sound to the program material and the environment. The controls have locks to prevent unwanted access after they have been adjusted. The loop amplifier is stackable (master/slave configuration) to cover very large areas, and supports low spillover schemes. Its unique quadrate configuration provides uniform field strengths even over multiple loops.
Controls and Indicators
Front
- LED power meter
- Current meter
- Four LEDS for fault, AGC, loop integrity
- Headphones socket
- Two tone controls
- Three input volume controls(master and two channels)
- On/Off switch
Back
- Metal loss compensation control
- Supervision switch
- Voltage selector
- Frequency range switch
Technical Specifications
| Mains power supply | |
| Voltage | 230/115 VAC, ±10%, 50/60 Hz |
| Inrush current | 7 A at 230 VAC / 14A at 115 VAC |
| Max power consumption | 500 VA |
| Performance | |
| Output current | 10 A |
| Frequency Response | 50 Hz to 10 kHz (+1/-3 dB at -10 dB ref. rated output) |
| Distortion | <1% at rated output power, 1kHz |
| Bass Control | -8/+8 dB at 100 Hz |
| Treble Control | -8/+8 dB at 10 kHz |
| Mic/Line Input | 2x |
| Connector | 3-Pin XLR, balanced mic/line level (switchable) |
| Sensitivity | 1mV/1V (mic/line) |
| Impedance | >1k ohm |
| Dynamic Range | 100 dB |
| S/N (flat at max volume) | 75 dB |
| Headroom | 25 dB |
| Phantom power supply | 16V (switchable) |
| VOX functionality | Input 1 (switchable) mutes input 2 |
| VOX sensitivity | -10dB ref nominal input |
| Priority input | |
| Connector | Screw |
| Sensitivity | 100V, transformer balanced |
| Impedance | >100 kohm |
| S/N (flat at max volume) | 63 dB |
| Headroom | 25 dB |
| Pilot tone detection | -20 dB, ref 100 V (10 V) |
| Pilot tone threshold | -26 dB, ref 100 V (5 V) |
| Master input* | 1 x |
| Connector | 1/4" TS jack |
| Line output | |
| Connector | 3-pin XLR, balanced |
| Nominal level | 1 V |
| Impedance | 200 ohm |
| Loop output | |
| Connector | Screw |
| Slave output | (for master input of other PLN-1LA10) |
| Connector | 1/4”TS jack 0° to 90° |
| Fault Relay | |
| Connector | Screw |
| Contacts | 100 V, 2 A (voltage free, SPDT) |
Mechanical
| Dimensions (H x W x D) | 94 x 430 x 320 mm
(19" wide, 2U high) |
| Weight | Approx. 11.6 kg |
| Mounting | Stand-alone, 19" rack |
| Color | Charcoal |
Enviromental
| Operating temperature | -10 ºC to +55 ºC (14 ºF to +131 ºF) |
| Storage and transport temperature | 40 ºC to +70 ºC (-40 ºF to +158 ºF) |
| Relative humidity | <95% |
| Acoustic noise level of fan | <35 dB SPL at 1m, temperature controlled |
